Aluminum nitride (AIN) has a hexagonal wurtzite crystal structure and a theoretical density of 3.26 g/cm. It has a low thermal expansion coefficient, a high thermal conductivity, and a high melting point. When fully densified, AlN is resistant to water and mineral acids at ambient temperatures and stable in air up to 1450.degree. C. The high temperature stability in air qualifies AlN as an excellent candidate for high temperature materials. However, the commercial AlN is usually contaminated with a large amount of oxygen in the form of Al.sub.2 O.sub.3 which adversely affects the desireable properties of the AlN.